Ventures are good close combat ships - I won't say great, but only because of their speed. Pretty much anything can get away from it. That said, the ship is monstrously tough - almost capital level armor and hull. Also, the closer it is to combat the faster fighters get back in the action.
Put a Heavy Blaster on the front - Voila, it has destroyer level firepower. Now take off one of the side flaks and put on a kinetic gun - suddenly the ship is very very dangerous.
The missiles don't have to be LRMs - I very much like the 5 shot reapers on it. Get brawling with an enemy cruiser, take some hits but drive up its flux, then flood it with 6 torpedoes. No more enemy cruiser. Granted this is better done as the player, and LRM's are a dependable choice for the AI.